Fix NPE if PW gets removed

forge-ai/src/main/java/forge/ai/ComputerUtilCombat.java

@@ -2521,10 +2521,8 @@ public class ComputerUtilCombat {
         if (combat != null) {
             // 1. If the card that spawned the attacker was sent at a planeswalker, attack the same. Consider improving.
             GameEntity def = combat.getDefenderByAttacker(sa.getHostCard());
-            if (def != null && def instanceof Card) {
-                if (((Card)def).isPlaneswalker()) {
-                    return def;
-                }
+            if (def != null && def instanceof Card && ((Card)def).isPlaneswalker() && defenders.contains(def)) {
+                return def;
             }
             // 2. Otherwise, go through the list of options one by one, choose the first one that can't be blocked profitably.
             for (GameEntity p : defenders) {

forge-ai/src/main/java/forge/ai/ability/AddTurnAi.java

@@ -46,6 +46,7 @@ public class AddTurnAi extends SpellAbilityAi {
         if (sa.usesTargeting()) {
             sa.resetTargets();
             if (sa.canTarget(ai)) {
+                // TODO check for Ugin's Nexus
                 sa.getTargets().add(ai);
             } else if (mandatory) {
             	for (final Player ally : ai.getAllies()) {